1. Field of the Invention
The present invention relates to a lens apparatus, in particular, a lens apparatus to be used for a stereoscopic camera which uses multiple lens apparatuses and camera apparatuses to take a parallax image in an image-taking system for stereoscopic camera.
2. Description of the Related Art
A stereoscopic image taking system which uses multiple image-pickup apparatuses, each being usable alone, to perform stereoscopic image taking is conventionally known. Two image-pickup apparatuses used for the stereoscopic image taking as described above are required to be driven simultaneously so that optical conditions of the two image-pickup apparatuses, which change depending on a state (position) of a target to be controlled such as a focus, a zoom and a stop, are always identical with each other.
For example, Japanese Patent No. 3,278,667 discloses a technology for synchronizing two lenses with each other by controlling a position signal of one of the lenses functioning as a master as a position command signal for the other lens corresponding to a slave-side lens. Moreover, Japanese Patent Application Laid-Open No. 2009-77090 discloses a camera, including a connector for connecting another camera, and a technology for performing control to perform stereoscopic image taking when the two cameras are connected to each other.
According to the related art disclosed in Japanese Patent No. 3,278,667, however, it is necessary to provide a circuit for synchronizing an operation of the slave lens with an operation of the master lens in each of the lens apparatuses or the controller. Moreover, according to the related art disclosed in Japanese Patent Application Laid-Open No. 2009-77090, a dedicated connector for connection of cameras is required to be provided to connect the two cameras to each other.
Therefore, the image-pickup apparatuses, each being usable alone, and the controller cannot be directly used for the stereoscopic image taking. Specifically, the circuit for synchronization control or the connection member is disadvantageously required to be additionally provided.